Leader of society inclined to be stiff (7)
I believe the answer is:
stilted
'stiff' is the definition.
(thesaurus)
'leader of society inclined' is the wordplay.
'leader of' suggests taking the first letters.
'inclined' becomes 'tilted' ('tilted' can be similar in meaning to 'inclined').
The initial letter of 'society' is 's'.
's'+'tilted'='STILTED'
'to be' is the link.
(Other definitions for stilted that I've seen before include "Awkward" , "Bombastic (of speech, writing)" , "Stiff and unnatural" , "Unnatural sounding and overformal" , "Stiff and pompous" .)